This invention is in the field of AC coupled FLIR video processing systems. A problem existing in these video processing systems is that of insufficient dynamic range because of smoke, dust, fire or background signals that are saturated at the output of the preamplifier or within the post amplifiers.
Some means is needed to vary the height of the pedestal (or low frequency) signals such that the perceivable scene dynamic range is enlarged to preserve the details (high frequency) signal at the display when the preamplifier output signal is very large.
It is an object of the present invention to provide a common module FLIR system with a higher degree of hands-off operation by replacing the existing manual gain control with an automatic gain control (AGC) circuit.
It is a further object to provide an automatic low frequency gain limiting circuit that expands the perceivable scene dynamic range and resolve the image streaking problems for airborne applications.
The present invention solves the above problems.